LM2757 Datasheet | National Semiconductor

Description The LM2757 is a constant frequency pre-regulated switchedcapacitor charge pump that operates at 1.25 MHz to produce a low-noise regulated output voltage. The device can be configured to provide up to 100 m A at 4.1V, 110 m A at 4.5V, or 180 m A at 5V. Excellent efficiency is achieved without the use of an inductor by operating the charge pump in a gain of either 3/2 or 2 according to the input voltage and output voltage option selection. The LM2757 presents a high impedance at the VOUT pin when shut down. This allows for use in applications that require the regulated output bus to be driven by another supply while the LM2757 is shut down. A perfect fit for space-constrained, battery-operated applications, the LM2757 requires only 4 small, inexpensive ceramic capacitors. LM2757 is a tiny 1.2 mm X 1.6 mm 12- bump micro SMD device. Built in soft-start, over-current protection, and thermal shutdown features are also included in this device. Features - Inductorless solution uses only 4 small ceramic - - - - - - - - - capacitors. True input-output and output-input disconnect. Up to 180 m A output current capability (5V). Selectable 4.1V, 4.5V or 5.0V output. Pre-regulation minimizes input current ripple. 1.24 MHz switching frequency for a low-noise, low-ripple output voltage. Efficient dual gain converter (2X, 3/2X). Integrated Over Current Protection. Integrated Thermal Shutdown Protection. Tiny 1.2 mm X 1.6 mm X 0.4 mm pitch, 12- bump micro SMD package. Applications - - - - - - - Keypad LED Drive USB/USB-OTG Power Cellular Phone SIM cards Audio amplifier power supplies Low-current Camera Flash General Purpose Li-Ion-to-5V Conversion Supercapacitor Charger Typical Application Circuit © 2007 National Semiconductor Corporation .national. Connection Diagram and Package Mark Information 12- Bump Micro SMD Package, 0.4mm Pitch National Semiconductor Package Number TMD12 .. Note 1: The actual physical placement of the...